Buggy code:
public abstract class Definer extends Task { private String name ; private String classname ; private File file ; private String resource ; private Delegate cpDelegate ; private boolean definerSet = false ; private ClassLoader internalClassLoader ; private int onError = Definer . OnError . FAIL ; private String adapter ; private String adaptTo ; private Class adapterClass ; private Class adaptToClass ; public static class OnError extends EnumeratedAttribute { public static final int FAIL = 0 ; public static final int REPORT = 1 ; public static final int IGNORE = 2 ; public OnError ( ) { } public OnError ( String value ) { } public String [ ] getValues ( ) { } } public void setOnError ( Definer . OnError onError ) { } public void setReverseLoader ( boolean reverseLoader ) { } public String getName ( ) { } public Path getClasspath ( ) { } public File getFile ( ) { } public String getResource ( ) { } public boolean isReverseLoader ( ) { } public String getLoaderId ( ) { } public String getClasspathId ( ) { } public void setClasspath ( Path classpath ) { } public Path createClasspath ( ) { } public void setClasspathRef ( Reference r ) { } public void setLoaderRef ( Reference r ) { } public void execute ( ) throws BuildException { } private URL fileToURL ( ) { } private URL resourceToURL ( ClassLoader classLoader ) { } protected void loadProperties ( ClassLoader al , URL url ) { } protected ClassLoader createLoader ( ) { } public void setFile ( File file ) { } public void setResource ( String res ) { } public void setName ( String name ) { } public String getClassname ( ) { } public void setClassname ( String classname ) { } public void setAdapter ( String adapter ) { } protected void setAdapterClass ( Class adapterClass ) { } public void setAdaptTo ( String adaptTo ) { } protected void setAdaptToClass ( Class adaptToClass ) { } protected void setInternalClassLoader ( ClassLoader classLoader ) { } public void init ( ) throws BuildException { } protected void addDefinition ( ClassLoader al , String name , String classname ) throws BuildException { Class cl = null ; try { try { if ( ( onError ) != ( Definer . OnError . IGNORE ) ) { cl = al . loadClass ( classname ) ; AntClassLoader . initializeClass ( cl ) ; } if ( ( adapter ) != null ) { adapterClass = al . loadClass ( adapter ) ; AntClassLoader . initializeClass ( adapterClass ) ; } if ( ( adaptTo ) != null ) { adaptToClass = al . loadClass ( adaptTo ) ; AntClassLoader . initializeClass ( adaptToClass ) ; } AntTypeDefinition def = new AntTypeDefinition ( ) ; def . setName ( name ) ; def . setClassName ( classname ) ; def . setClass ( cl ) ; def . setAdapterClass ( adapterClass ) ; def . setAdaptToClass ( adaptToClass ) ; def . setClassLoader ( al ) ; if ( cl != null ) { <START_BUG> def . checkClass ( project ) ; <END_BUG> } ComponentHelper . getComponentHelper ( getProject ( ) ) . addDataTypeDefinition ( def ) ; } catch ( ClassNotFoundException cnfe ) { String msg = ( ( ( getTaskName ( ) ) + "<seq2seq4repair_space>class<seq2seq4repair_space>" ) + classname ) + "<seq2seq4repair_space>cannot<seq2seq4repair_space>be<seq2seq4repair_space>found" ; throw new BuildException ( msg , cnfe , getLocation ( ) ) ; } catch ( NoClassDefFoundError ncdfe ) { String msg = ( ( ( ( getTaskName ( ) ) + "A<seq2seq4repair_space>class<seq2seq4repair_space>needed<seq2seq4repair_space>by<seq2seq4repair_space>class<seq2seq4repair_space>" ) + classname ) + "<seq2seq4repair_space>cannot<seq2seq4repair_space>be<seq2seq4repair_space>found:<seq2seq4repair_space>" ) + ( ncdfe . getMessage ( ) ) ; throw new BuildException ( msg , ncdfe , location ) ; } } catch ( BuildException ex ) { switch ( onError ) { case Definer . OnError . FAIL : throw ex ; case Definer . OnError . REPORT : log ( ( ( ( ex . getLocation ( ) ) + "Warning:<seq2seq4repair_space>" ) + ( ex . getMessage ( ) ) ) , MSG_WARN ) ; break ; default : log ( ( ( ex . getLocation ( ) ) + ( ex . getMessage ( ) ) ) , MSG_DEBUG ) ; } } } private void tooManyDefinitions ( ) { } }

Fix:
def . checkClass ( getProject ( ) ) ;